berglund



R. M. BERGLUND V 2,456,615

Dec. 21, 1948.

" METHOD OF MAKING VENT VALVES FOR CONTAINERS 2 Sheets-Sheet l Filed Aug. 23, 1944 SOURCE OF STEAM INVEN Filed Aug. 23, 1944 R. M. BERGLUND 2,456,615 ETHOD OF MAKING VENT VALVES FOR CONTAINERS 2 Sheets$heet 2 Patented Dec. 21, 1948 :METHOD F M'A'KIN G VENT VALVES FOR CONTAINERS 'jRa lph Berglund, Seattle, 'Wash., assignor to American Gan Company,

New York, N. Y., a

corporation of NewJersey Application August 23, 1944,

Serial No.;550,.744

' 3 Claims. (Cl.1859') This invention relates to the manufacture of vent valves for-can parts and has particularreference to molding a yieldable valve material in po ition on the perforated .wall of a can to provide a vent valve container for food products,

The invention contemplates an improved simolemolding process for-.producinga r ibbercr sim lar-material yieldable valve for a cameo that normallv the valve closes a vent opening in the can. Some materials. such as cheese for ex.- ample. requirea ,rineningaction andcheese may be sealed successfully.incontainers, provided the container is of a construction vto allow for escape of gases created. during the ri ening process and provided. the container prevents passage of air into the container. .Itis tothenovelcreation of a desirediormof yieldable valve on a container Wall that thisinvention is particularly directed.

An obiect of the invention is the provision of a method for making a vent avalvezby pressing a yieldable material such as .rubber against a can end or other pontainerpartand to extrude a :pa t of th rub e Fl h i TMQHE Q 01821 forations in thecontainer :tO secure the valve to the can end with --thread-;or-.neck';l il e connecting elements so that the :bodyof :the qvalve covers which the valved end is used.

A further object of=the invention is the provision of a method ot-molding a yieldable valve 'be had.

raf ,theelqnlicationaniiiiqrmatieng th ven valve, parts being broken awayand parts shown in section;

.Fig. 3 is a sectional view drawn to an enlarged onto a panelzwall of a can end 'in a slightly differentmanner. parts being brokenaway;

' F g. 5 is a fragmentary-sectional view on a reduced scale showing a typical drying machine converted to the heating of the molded vent valve formed on a can .end so that by heat treatment the valve is cured and is conditioned for use;

Fig. 6 is a fragmentary sectional view drawn to the same scale as Fig. 4 and showing die membars for reforming a portion of a can end with its applied vent-valve as a preloading step for setting the pressure release point of the valve; and

Fig. 7 is a perspective view of the upper portion of a can end with its applied completed valve.

As a'preferred embodiment of the invention the drawings disclose can end parts and principal tral vent opening C formed in a raised central panel D. In the form illustrated inFig. l perforations E surround the vent opening C and are preferably equally ,spaced in a concentric circle. This is exemplary of a can part suitable for receiving-the vent valve A.

The "first step in the present method of producing vent valves A comprisesforcing a yieldable material suchas, rubber, into position, preferably while heated, soflthat the vent valve iSmO dQd-J n place on the canend. ,In this formationof the valve, adorned disc F (Fig. .2)k,results -fromethe application ofthe rubber .to theexterior surface pf the can end and thi disc F tegral ring H.

'As best illustrated in Fig. 3 the preferred form One or. both-of "these blocks may 'be movable .;rel-

,ple l sans the-vent pening .c @of trend. In

inserted position the inner face of the boss I2 is, substantially flush with the Outer wall of the located can end.

The block ill has a disc forming mold cavity,

recess or depression l3 sunk in its inner face and is shaped to provide for the disc F. The block H has an annular mold cavity, recess or depression l4 on its adjacent semi-circular in cross section and providing for the molded valve ring H.

Blocks l and H preferably are heated as this assists in a heating medium has been found to be satisfactory and accordingly the mold blocks are conmind. The block 10 is formed with a heating chamber 15 into which steam. may be introduced from a supply pipe l6 connecting by a passageway or port H with the heating chamber. Steam is circulated through the block and from the chamber I it is discharged through a passageway or port I8 into a discharge pipe is.

In. a similar manner, block ll may be steam heated. For this purpose a heating chamber 2| is formed in the block and steam is supplied by an inlet pipe 22 by way of a passageway or port 23. Steam, from chamber 2! is discharged through a passageway or port 24 and thence through a discharge pipe 25. In this manner both mold blocks I0 and I I may be maintained at the desired temperature, the type of rubber or other molding material determining the actual heat required.

-1When the blocks ill and H are in closed position as in Fig. 3. with the inserted end B in place, rubber or the like confined within a supply well 28 formed in block i0, is forced through a port 29 into the mold cavity or recess l3. This may be done in any suitable manner as by means of a piston 31 secured to the lower end of an actuatin rod 32. i

As the heated rubber is forced through the port 29 into the molding recess l3 it completely fills the recess and an excess portion flows through the perforations E and into the valve ring mold recess M of the block H. To insure'that all of the spaces l3, l4 and perforations E be completely filled, a vent port 33 extends from the recess 14 in the block I l to a vertically disposed vent passageway or port 34. Provision is also made for the passage of some rubber directly from the molding recess l3 through the boss I2 by means Of a port 35 also connecting with the passageway 34.

After the molding step the block members H], H are separated and the can end B with its attached vent valve A is removed from the mold. Owing to the small diameter of the ports 29, 33 and 35. any extruded rubber confined in the ports will be broken off as the valve A is taken out of the mold.

, The description of molding a vent valve in place on a can'end thus far has contemplated forming the valve from semi-liquid or jellied rubber. In Fig. 4 there is disclosed an apparatus for effecting a slightly different molding step. The apparatus of this modified form comprisesa valve disc molding block 48 and a valve ring molding block 49. The molding blocks may be movable relative toeach other the block 48 being movable as shown in the drawing. A can end B is placed between the molding blocks. A rod 50 disposed in the block 49 provides a support for the can end, its inner end being inserted in the vent opening C of the can end.

The inner face of mold block 48 is recessed as a disc shaped mold 5| to accommodate or provide for the domed valvedi sc F. In like manner the inner face of the mold block 49 has a mold recess 52 providing for the molded valve ring H. The movable molding block 48 is mounted in a movable sleeve 53. According to this modified molding step as effected in the apparatus shown in Fig. 4, a preformed disc P of rubber or other face, this depression being ber. This rubberdisc I Vab1e block the molding operation. Live steam a suitable material is used instead of the jellied rubis inserted between the can end B, on its rod 50, and the inner face of the 48. The disc P is lightly held in the recessed end of the block by sliding of the rod 50 forward (toward the left, Fig. 4) to engage the disc. With the rubber disc P in inserted position, the sleeve 53 is moved toward the blocl 49 until its inner face engages against the can end B held in the block. This fully confines the rubber disc P within the .mold parts. The block 48 then is moved toward the right for the molding operation.

Provision is made for heating both of the molding blocks 48, 49. For this purpose an inner chamber 54 is formed in the block 48. Live steam or other suitable heating media is circulated into and through the chamber by means of an inlet pipe 55 and a connectin passagewayleading into the chamber and by a passageway to a discharge pipe 56 leading from the chamber.

In a similar manner. the blocl 49 is provided with a heating chamber, live steam being introduced into the chamber by way of an inlet pipe 53 and a connecting passageway, the steam escaping through a passageway and into a discharge pipe 59. The sleeve 53 is slotted as shown to allow for clearance of the pipes 55, 56 during movement of the block 48. 1

To insure complete filling of the molds during the transformation of the disc P into a valve A, a portBU is formed'in the block 49. communicates with the groove or mold recess 52 and also connects with a vent passageway or port 6|. The excess of rubber contained in the disc P over that needed for molding thevalve A is forced into the channels 60. BI as in the instance of the former described die parts of Fig. 3. Thus it will be seen that the same vent valve A is produced regardless of whether the apparatus of Fig. 3 or the modified apparatus of Fig. 4 is used.

For most purposes the molded valve A is only in a raw condition and further curing of the rubber is desirable. This curing of the valve is best effected in a heating and drying operation which may be performed in atypical can end drying apparatus. Fig. principal parts of such an apparatus which is more fully described in the Horace J. Paynter United States Patent 1,754,483, issued April 15, 1930. Such an apparatus includes a chain conveyor 55 having spaced feed dogs 56 on which the can ends B with their molded valves A may be placed for advancement into the drying apparatus. Such a conveyor places each can end into a rotary can end conveyor or feeding device 61.

Such a conveyor rotates within a heat insulated housing 68 enclosing a drying chamber 59. The drying chamber may be maintained at a substantially uniform temperature for the proper curing of the vent valves. This may be done with heated air and is similar to the drying of lined can ends as in the manner fully described in the aforesaid Paynter patent. It is during relatively slow passage of the can ends within the drying chamber that the vent valves A are'fully cured and conditioned for proper operations. The cured valve can end or cover units after passage through the This port 5 illustrates a portion of the.

drying chamber are discharged as illustrated in Fig. onto a discharge conveyor 10, a platform or other suitable place of deposit for further treatment.

rounding edge could be reformed into a flange as by a shinning action.

In Fig. 6 is shown a die eludes an upp r die member 15 and a lower die pocket or recess 18 conform to the shape valve.

the walls of which closely of the domed disc F of the I claim: 1. The method of molding and securing a mem ber composed of yieldable material in position on opening after said end has been secured to a can body filled with a gas generating product.

can end to fill the thereafter to excompress said disc against the recess in one die member and gas pressure to permit escape of such gas through the can end vent opening after said end has been secured to a can body filled with a gas generating product.

RALPH M. BERGLUN D.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,784,780 Bronson Dec. 9, 1930 2,068,481 Brown 1 Jan. 19, 1937 2,209,403 Kittner et a1. July 30, 1940 2,329,346 Goff Sept. 14, 1943 

